The invention relates to picture frames, especially clamps that are used to hold the mitered corners of a popular, contemporary metal picture frame together. This particular frame is composed of metal framing members that have rearwardly facing, recessed channels that are defined between a flat bottom and a pair of opposing flanges which are spaced to form between them a slot which extends longitudinally of the channel and members.
At present, the clamping device used for holding the mitered corners of adjacent framing members together, consists of an L-shaped plate with outstanding legs that are designed to fit in the channels of adjacent members. A conventional machine screw is provided in each of the legs to securely fasten a plate within the intersecting channels of each mitered corner. The invention is directed to the provision of a self-operating clamp which needs no outside tool for its operation.